Libby Expected to Expand Legal Team

WASHINGTON -- The good news for Vice President Dick Cheney's former chief of staff, I. Lewis "Scooter" Libby, is that perjury and related charges can be difficult to prove, especially when the underlying crime being investigated isn't among those being alleged, defense lawyers and former prosecutors say.

But Mr. Libby's defense could prove challenging, given his background as a lawyer and the detailed information compiled...